OCEAN ACIDIFICATION

18 May 2015

When it comes to the health of our oceans, one of the biggest concerns is the acidification of the water by the actions that humans have had on the planet due to industrialization. While the effect is an indirect one, it is having a powerful effect on the ocean, lakes and rivers of the world.

What is Ocean Acidification?

Basically, this is the decrease in the pH balance in the oceans which is caused by the rise of carbon dioxide (CO2) being absorbed from the atmosphere. It is currently estimated that up to 40% of the carbon dioxide that is released by humans is being absorbed into the bodies of water around our planet. The effect is that the reaction of CO2 in the ocean forms carbonic acid that reacts with water molecules to create a hydronium and bicarbonate ion which increases the acids levels of the water.

The acidification of the ocean is believed to have begun in the mid-18th century and has been increasing over time as industrialization has spread around the Earth. It is estimated that the surface ocean pH has been reduced from 8.25 to 8.14. In addition, the H+ ions have increased their concentration by almost 30% over that time as well. The fear is that the oceans may have reached a point where the acidifications will greatly disrupt the marine life and ecosystems of the oceans. In other words, the marine life as we know it may cause many harmful consequences that will affect life around the Earth.

The Consequences of Ocean Acidification

There are a number of harmful effects that this process will have as it increases over time which includes the following;

Coral Bleaching

Decreased Metabolic Rates & Immune Responses of Marine Life

The Destruction of Algae

There are other considerations as well such as the chemical reactions that may decrease the carbonate ions which are available in the ocean. Life such as certain plankton and coral will find the ocean more unsuitable to live while being threatened with dying off in great numbers if the acidification keeps occurring. This will disrupt the food chain in the ocean which may result in many larger species becoming threatened as well.

The acidification of the ocean due to the introduction of more CO2 has happened before in Earth’s history during what was known as the Paleocene Eocene Thermal Maximum which was roughly 56 million years ago. For reasons that no one has yet discovered, a massive amount of carbon entered the ocean and the atmosphere which resulted in all the carbonate sediments in the basins of the oceans to undergo dissolution.

The Future Effects of Acidification

The negative effects of acidification based on past occurrences may have devastating consequences for the future of marine life in the oceans of the world. The collapse of what is known as food webs is certainly one of the worst consequences that might happen. Basically, a food web or food chain is one where the smaller calcium carbonate shells of the marine life are so harmed by acidification that they start dying off and take the larger fish and mammals that consume them for food with them.

In addition to coral and certain types of plankton, pteropods which are small sea snails are vulnerable to the acidification of the ocean as well. They are the primary source of food for different predators which include whales up in the arctic waters. It is estimated that if the acid levels continue to rise, by the end of the 21st century, they will be dying off in large numbers. When they are gone, the consequences for the rest of the marine life will be in dire straits.

Other creatures that are vulnerable include sea urchins that help protect the coral reefs from algae. If they start to die off by the end of the 21st century, it will also adversely affect the predators who feed on them as well. Sea urchins because of their shells are very vulnerable to this form of CO2 increase and what it does to the sea water.

Brittle stars are another form of life that is very vulnerable to acidification as well, particularly the larvae which may not mature into adults if this process continues. Brittle stars that do manage to reach adulthood will lose their muscle mass and may not be able to regenerate if they should lose an appendage.

Indirect effects will include squid who will find it harder to find the energy to swim effectively because of the reduced amount of oxygen in their bloodstream because of contact with the acid buildup in the oceans. Sperm and beaked whales feed on squid and will reduce their population to dangerous levels if they cannot find the energy to swim away fast enough. Plus, squid fisheries are big business in California for example where they create tens of millions of dollars in revenue.

Even certain fish may be vulnerable to this process as well, especially in the larvae stages where they are quite weak and susceptible to changes in the ocean. Damselfish and clownfish for example in the larvae stages may have difficulty finding food and swimming with the energy needed to escape predators. This will result in more fish not reaching the adult stage which in turn means even more species become vulnerable to extinction.

In the end, ocean acidification may have dire consequences if action is not taken in a prompt manner. With so many species of marine life either directly or indirectly threatened, the potential loss is enormous which means that lives of those that feed off the ocean are vulnerable as well. The protection of ocean life is paramount to the survival of so many species both in and outside the waters that governments around the world are taking notice at what is happening. Whether action can be taken soon enough before the tipping point passes is another matter which will have to be carefully viewed in order to ensure the survival of life in our oceans.